open-consul/api/discovery_chain.go

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// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package api
import (
"encoding/json"
"fmt"
"time"
)
// DiscoveryChain can be used to query the discovery-chain endpoints
type DiscoveryChain struct {
c *Client
}
// DiscoveryChain returns a handle to the discovery-chain endpoints
func (c *Client) DiscoveryChain() *DiscoveryChain {
return &DiscoveryChain{c}
}
func (d *DiscoveryChain) Get(name string, opts *DiscoveryChainOptions, q *QueryOptions) (*DiscoveryChainResponse, *QueryMeta, error) {
if name == "" {
return nil, nil, fmt.Errorf("Name parameter must not be empty")
}
method := "GET"
if opts != nil && opts.requiresPOST() {
method = "POST"
}
r := d.c.newRequest(method, fmt.Sprintf("/v1/discovery-chain/%s", name))
r.setQueryOptions(q)
if opts != nil {
if opts.EvaluateInDatacenter != "" {
r.params.Set("compile-dc", opts.EvaluateInDatacenter)
}
}
if method == "POST" {
r.obj = opts
}
rtt, resp, err := d.c.doRequest(r)
if err != nil {
return nil, nil, err
}
defer closeResponseBody(resp)
if err := requireOK(resp); err != nil {
return nil, nil, err
}
qm := &QueryMeta{}
parseQueryMeta(resp, qm)
qm.RequestTime = rtt
var out DiscoveryChainResponse
if err := decodeBody(resp, &out); err != nil {
return nil, nil, err
}
return &out, qm, nil
}
type DiscoveryChainOptions struct {
EvaluateInDatacenter string `json:"-"`
// OverrideMeshGateway allows for the mesh gateway setting to be overridden
// for any resolver in the compiled chain.
OverrideMeshGateway MeshGatewayConfig `json:",omitempty"`
// OverrideProtocol allows for the final protocol for the chain to be
// altered.
//
// - If the chain ordinarily would be TCP and an L7 protocol is passed here
// the chain will not include Routers or Splitters.
//
// - If the chain ordinarily would be L7 and TCP is passed here the chain
// will not include Routers or Splitters.
OverrideProtocol string `json:",omitempty"`
// OverrideConnectTimeout allows for the ConnectTimeout setting to be
// overridden for any resolver in the compiled chain.
OverrideConnectTimeout time.Duration `json:",omitempty"`
}
func (o *DiscoveryChainOptions) requiresPOST() bool {
if o == nil {
return false
}
return o.OverrideMeshGateway.Mode != "" ||
o.OverrideProtocol != "" ||
o.OverrideConnectTimeout != 0
}
type DiscoveryChainResponse struct {
Chain *CompiledDiscoveryChain
}
type CompiledDiscoveryChain struct {
ServiceName string
Namespace string
Datacenter string
// CustomizationHash is a unique hash of any data that affects the
// compilation of the discovery chain other than config entries or the
// name/namespace/datacenter evaluation criteria.
//
// If set, this value should be used to prefix/suffix any generated load
// balancer data plane objects to avoid sharing customized and
// non-customized versions.
CustomizationHash string
// Default indicates if this discovery chain is based on no
// service-resolver, service-splitter, or service-router config entries.
Default bool
// Protocol is the overall protocol shared by everything in the chain.
Protocol string
// ServiceMeta is the metadata from the underlying service-defaults config
// entry for the service named ServiceName.
ServiceMeta map[string]string
// StartNode is the first key into the Nodes map that should be followed
// when walking the discovery chain.
StartNode string
// Nodes contains all nodes available for traversal in the chain keyed by a
// unique name. You can walk this by starting with StartNode.
//
// NOTE: The names should be treated as opaque values and are only
// guaranteed to be consistent within a single compilation.
Nodes map[string]*DiscoveryGraphNode
// Targets is a list of all targets used in this chain.
//
// NOTE: The names should be treated as opaque values and are only
// guaranteed to be consistent within a single compilation.
Targets map[string]*DiscoveryTarget
}
const (
DiscoveryGraphNodeTypeRouter = "router"
DiscoveryGraphNodeTypeSplitter = "splitter"
DiscoveryGraphNodeTypeResolver = "resolver"
)
// DiscoveryGraphNode is a single node in the compiled discovery chain.
type DiscoveryGraphNode struct {
Type string
Name string // this is NOT necessarily a service
// fields for Type==router
Routes []*DiscoveryRoute
// fields for Type==splitter
Splits []*DiscoverySplit
// fields for Type==resolver
Resolver *DiscoveryResolver
// shared by Type==resolver || Type==splitter
LoadBalancer *LoadBalancer `json:",omitempty"`
}
// compiled form of ServiceRoute
type DiscoveryRoute struct {
Definition *ServiceRoute
NextNode string
}
// compiled form of ServiceSplit
type DiscoverySplit struct {
Weight float32
NextNode string
}
// compiled form of ServiceResolverConfigEntry
type DiscoveryResolver struct {
Default bool
ConnectTimeout time.Duration
Target string
Failover *DiscoveryFailover
}
func (r *DiscoveryResolver) MarshalJSON() ([]byte, error) {
type Alias DiscoveryResolver
exported := &struct {
ConnectTimeout string `json:",omitempty"`
*Alias
}{
ConnectTimeout: r.ConnectTimeout.String(),
Alias: (*Alias)(r),
}
if r.ConnectTimeout == 0 {
exported.ConnectTimeout = ""
}
return json.Marshal(exported)
}
func (r *DiscoveryResolver) UnmarshalJSON(data []byte) error {
type Alias DiscoveryResolver
aux := &struct {
ConnectTimeout string
*Alias
}{
Alias: (*Alias)(r),
}
if err := json.Unmarshal(data, &aux); err != nil {
return err
}
var err error
if aux.ConnectTimeout != "" {
if r.ConnectTimeout, err = time.ParseDuration(aux.ConnectTimeout); err != nil {
return err
}
}
return nil
}
// compiled form of ServiceResolverFailover
type DiscoveryFailover struct {
Targets []string
Policy ServiceResolverFailoverPolicy `json:",omitempty"`
}
// DiscoveryTarget represents all of the inputs necessary to use a resolver
// config entry to execute a catalog query to generate a list of service
// instances during discovery.
type DiscoveryTarget struct {
ID string
Service string
ServiceSubset string
Namespace string
Datacenter string
MeshGateway MeshGatewayConfig
Subset ServiceResolverSubset
ConnectTimeout time.Duration
External bool
SNI string
Name string
}
func (t *DiscoveryTarget) MarshalJSON() ([]byte, error) {
type Alias DiscoveryTarget
exported := &struct {
ConnectTimeout string `json:",omitempty"`
*Alias
}{
ConnectTimeout: t.ConnectTimeout.String(),
Alias: (*Alias)(t),
}
if t.ConnectTimeout == 0 {
exported.ConnectTimeout = ""
}
return json.Marshal(exported)
}
func (t *DiscoveryTarget) UnmarshalJSON(data []byte) error {
type Alias DiscoveryTarget
aux := &struct {
ConnectTimeout string
*Alias
}{
Alias: (*Alias)(t),
}
if err := json.Unmarshal(data, &aux); err != nil {
return err
}
var err error
if aux.ConnectTimeout != "" {
if t.ConnectTimeout, err = time.ParseDuration(aux.ConnectTimeout); err != nil {
return err
}
}
return nil
}